These views from the Multi-angle Imaging SpectroRadiometer (MISR)
illustrate ice surface textures and cloud-top heights over the Amery Ice
Shelf/Lambert Glacier system in East Antarctica on October 25, 2002.

The left-hand panel is a natural-color view from MISR’s
downward-looking (nadir) camera. The center panel is a multi-angular
composite from three MISR cameras, in which color acts as a proxy for
angular reflectance variations related to texture. Here, data from the
red-band of MISR’s 60° forward-viewing, nadir and 60° backward-viewing
cameras are displayed as red, green and blue, respectively. With this
display technique, surfaces which predominantly exhibit
backward-scattering (generally rough surfaces) appear red/orange, while
surfaces which predominantly exhibit forward-scattering (generally
smooth surfaces) appear blue. Textural variation for both the grounded
and sea ice are apparent. The red/orange pixels in the lower portion of
the image correspond with a rough and crevassed region near the
grounding zone, that is, the area where the Lambert and four other
smaller glaciers merge and the ice starts to float as it forms the Amery
Ice Shelf. In the natural-color view, this rough ice is spectrally blue
in color.

Clouds exhibit both forward and backward-scattering properties in the
middle panel and thus appear purple, in distinct contrast with the
underlying ice and snow. An additional multi-angular technique for
differentiating clouds from ice is shown in the right-hand panel, which
is a stereoscopically derived height field retrieved using automated
pattern recognition involving data from multiple MISR cameras. Areas
exhibiting insufficient spatial contrast for stereoscopic retrieval are
shown in dark gray. Clouds are apparent as a result of their heights
above the surface terrain. Polar clouds are an important factor in
weather and climate. Inadequate characterization of cloud properties is
currently responsible for large uncertainties in climate prediction
models. Identification of polar clouds, mapping of their distributions,
and retrieval of their heights provide information that will help to
reduce this uncertainty.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth
continuously and every 9 days views the entire Earth between 82 degrees
north and 82 degrees south latitude. The MISR Browse Image Viewer provides access to
low-resolution true-color versions of these images. These data products were generated
from a portion of the imagery acquired during Terra orbit 15171. The
panels cover an area of 380 kilometers x 984 kilometers, and utilize
data from blocks 145 to 151 within World Reference System-2 path 127.